Key Safety and Dosing Considerations for GLP-1 Agonists in Oncology Care

At the San Antonio Breast Cancer Symposium, Elvis Obomanu, M.B.B.S., LMCC, highlighted key considerations for using GLP-1 receptor agonists in patients with both diabetes and cancer. He noted that although retrospective findings suggest potential benefits, including anti-inflammatory effects, prospective trials are needed to confirm their role in oncology care.

Obomanu emphasized careful attention to dosing and adverse effects, as GLP-1 agents may both support chemotherapy tolerance and cause their own side effects. He also stressed the importance of monitoring for potential drug-drug interactions with chemotherapy, immunotherapy, and supportive care agents as clinicians and pharmacists evaluate how best to integrate GLP-1 agonists into cancer treatment.

Pharmacy Times: Your analysis showed remarkably consistent reductions in chemotherapy-related toxicities across hematologic, GI, cardiovascular, and systemic domains. What potential mechanisms do you believe explain the protective effect of GLP-1 receptor agonists during cytotoxic therapy?

Elvis Obomanu: Yeah, great. That’s a very good question. GLP-1 agents, beyond their effects on reducing blood glucose, have been found to have what we call pleiotropic effects. These effects span many areas, including anti-inflammatory actions. Several studies have shown that their effects across multiple systems may be related to these anti-inflammatory properties, as they reduce inflammatory mediators and pro-inflammatory cytokines.

In addition, they have been found to modulate immune function. Recently, I was reading about a study—the ELAD study—on the use of GLP-1 agonists in people with Alzheimer’s disease. Researchers speculated that the observed benefits may be due to anti-inflammatory mechanisms.

Furthermore, their actions on glucose need to be taken into account. By reducing glucose concentrations in the blood, they also contribute to weight reduction, which itself could explain some of the positive effects seen across various systems that have been studied.

Pharmacy Times: Given that GLP-1 RAs are already widely prescribed for diabetes and weight management, what considerations should clinicians—and pharmacists in particular—keep in mind when co-managing these agents in patients actively undergoing chemotherapy?

Elvis Obomanu: This question actually came up a couple of days ago, so I’m glad to address it further here. For patients who have both diabetes and cancer—especially in light of our study, which was a retrospective trial—if these findings were validated in a prospective or randomized controlled trial, I think clinicians and pharmacists would need to pay close attention to the dose of the GLP-1 agent being used.

The reason is that, although GLP-1 agonists may have positive effects—potentially improving adverse events associated with chemotherapy—some patients also experience adverse effects from the GLP-1 drug itself. So the question becomes: would clinicians feel comfortable prescribing higher doses, or would they need to be more conservative?

We also have to carefully consider the adverse events associated with GLP-1 agonists and how these agents may affect different tissues in the body. Finally, I would highlight the importance of evaluating drug–drug interactions. Although information is still limited, pharmacists and clinicians should be mindful of how GLP-1 agonists might interact with chemotherapy, immunotherapy, or even antiemetic drugs when used together.